no. 387 liverpool road strathfield nsw 2135 · reference to the sydney 1:100,000 geological series...

25th September 2015 Ref: GS6365-1A Nos. 28-30 Dumaresq Street Gordon NSW2072 Geotechnical Investigation Report of 16

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GEOTECHNICAL INVESTIGATION REPORT

No. 387 Liverpool Road Strathfield NSW 2135

Prepared for

Dora Christodoulides

Report No. GS6528-1A

20th May 2016

20th May 2016 Ref: GS6528-1A No. 387 Liverpool Road, Strathfield, NSW 2135 Geotechnical Investigation Report of 16

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CONTROLLED DOCUMENT

DISTRIBUTION AND REVISION REGISTER

Copy No. Custodian Location

_________________________________________________________________________

1 Nick Kariotoglou Aargus (Library)

2, 3 Dora Christodoulides C/O- Helen Pericleous

387 Liverpool Road

Strathfield, NSW 2135

4 (Electronic) [email protected]

Note: This register identifies the current custodians of controlled copies of the subject

document.

It is expected that these custodians would be responsible for:

The storage of the document.

Ensuring prompt incorporation of amendments.

Making the document available to pertinent personnel within the organisation.

Encouraging observance of the document by such personnel.

Making the document available for audit.

DOCUMENT HISTORY

Revision No. Issue Date Description

_____________________________________________________________________

0 20/05/2016 First Issue

Issued By:

Kenneth Burgess


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TABLE OF CONTENTS

1. INTRODUCTION..................................................................................... 5

2. AVAILABLE INFORMATION .............................................................. 5

3. SCOPE OF WORK .................................................................................. 5

4. SITE DESCRIPTION ............................................................................... 6

5. PROPOSED DEVELOPMENT .............................................................. 6

6. SUBSURFACE CONDITIONS ............................................................... 7

6.1 Geology ................................................................................................................................................ 7

6.2 Ground Profile .................................................................................................................................... 7

6.3 Groundwater ...................................................................................................................................... 8

7. GEOTECHNICAL ASSESSMENT ........................................................ 8

7.1 General ................................................................................................................................................ 8

7.2 Excavation Conditions ....................................................................................................................... 8

7.3 Vibration Control ............................................................................................................................... 9

7.4 Stability of Excavation ....................................................................................................................... 9

7.5 Earth Pressures ................................................................................................................................ 11

7.6 Subgrade Preparation and Earthworks ......................................................................................... 13

7.7 Foundations ...................................................................................................................................... 14

7.8 Groundwater Management ............................................................................................................. 15

7.9 Preliminary Site Earthquake Classification .................................................................................. 15

8. LIMITATIONS ....................................................................................... 15


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LIST OF TABLES

Table 1: Summary of Subsurface Conditions 7

Table 2: Recommended Maximum Peak Particle Velocity 9

Table 3: Recommended Batter Slopes (Temporary) 10

Table 4: Preliminary Geotechnical Design Parameters for Retaining Walls 12

Table 5: Preliminary Coefficients of Lateral Earth Pressure 12

Table 6: Preliminary Geotechnical Foundation Design Capacities 14

LIST OF APPENDICES

APPENDIX A IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL REPORT

APPENDIX B SITE PLAN (FIGURE 1)

APPENDIX C ENGINEERING BOREHOLE LOGS

REFERENCES

1. Australian Standard – AS 1726-1993 Geotechnical Site Investigation. 2. Australian Standard – AS 1170.4-2007 Structural Design Actions – Part 4:

Earthquake actions in Australia. 3. Australian Standard – AS3798-2007 Guidelines on Earthworks for Commercial and

Residential Developments. 4. Australian Standard – AS 2870-2011 Residential slabs and footings. 5. Australian Standard – AS 2159-2009 Piling - Design and installation. 6. Pells P.J.N, Mostyn, G. & Walker B.F., “Foundations on Sandstone and Shale in the

Sydney Region”, Australian Geomechanics Journal, 1998.


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1. INTRODUCTION

Aargus Pty Ltd (Aargus) has been commissioned by Dora Christodoulides to carry out a geotechnical site investigation at No. 387 Liverpool Road, Strathfield, NSW 2135. The site investigation was carried out on the 8th April 2016 and was followed by geotechnical interpretation, assessment and preparation of a geotechnical report.

The purpose of the investigation was to assess the ground conditions and feasibility, from a geotechnical perspective, of the site for a proposed residential development.

This report presents results of the geotechnical site investigation, laboratory testing, interpretation, and assessment of the site existing geotechnical conditions, as a basis to provide recommendations for design and construction of ground structures for the proposed development.

To assist in reading the report, reference should be made to the “Important Information About Your Geotechnical Report” attached as Appendix A.

2. AVAILABLE INFORMATION

Prior to preparation of this report, the following information was made available to Aargus:

Preliminary Architectural drawings titled “387 Liverpool Road, South Strathfield – Part A DP 321 566” prepared by Aleksandar Design Group, referenced project No. 1465 and included drawing nos. DA03 to DA10 inclusive; and

Site Survey plan titled “Detail Survey 387 Liverpool Road, Strathfield” prepared by Benchmark Surveys Pty Ltd, referenced No. 141019 and dated 13th October 2014.

3. SCOPE OF WORK

In accordance with the brief, fieldwork for the geotechnical site investigation was carried out by an experienced Geotechnical Engineer from Aargus; following in general the guidelines provided in Australian Standard AS 1726-1993 (Reference 1) and comprised the following:

Collection and review of Dial-Before-You-Dig (DBYD) plans; A site walkover inspection in order to determine the overall surface conditions and

to identify any relevant site features; Service locating using electromagnetic detection equipment to ensure that the

investigation area is free from underground services; Machine drilling of three (3) boreholes identified as BH1 to BH3 inclusive, using a

Dando Terrier Mini Drilling Rig owned and operated by a subcontractor; Standard Penetration Tests (SPT) was conducted within the machine drilled

boreholes to assess the in-situ strength of subsurface soil layers; Collection of soil and rock core samples during drilling; and Reinstatement of the boreholes with soil cuttings generated from the auger drilling

and excavation process.

The approximate locations of the boreholes completed during the geotechnical site investigation are shown on “Figure 1 - Site Plan” attached in Appendix B.


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Boreholes BH1 to BH3 inclusive were augered to Tungsten Carbide (TC) refusal at depths of approximately 6.2m, 4.5m and 6.8m below ground level (bgl), respectively.

Based on the results of the site investigation and laboratory testing, Aargus carried out geotechnical interpretation and assessment of the main potential geotechnical issues that may be associated with the proposed development. A geotechnical report (this report) was prepared to summarise the results of the geotechnical site investigation and to provide comments and recommendations relating to:

Excavation conditions; Stability of basement excavation; Suitable foundations; Allowable bearing pressure (and shaft adhesion for piles); Lateral pressure for design of retaining walls; Groundwater; and Site earthquake classification.

4. SITE DESCRIPTION

The site is an irregular shaped land with an approximate area of 843m2, and consists of the property No. 387 Liverpool Road.

At the time of the investigation, a single storey residential dwelling positioned in the front portion of the site (along Liverpool Road) was present; covering an area up to the middle portion of the site. A brick garage/shed was also present within the middle to rear portion of the site, adjoining the site southern boundary. The remaining site area was covered with a concrete driveway, well-maintained grass, and a number of mature trees.

The site is located within the Strathfield Municipal Council area, adjoining Liverpool Road carriageway, which a major road reserve within the local area. The site is bounded by the following properties, public roads and infrastructure:

High Street carriageway and road reserve to the north of the site; Liverpool Road carriageway and road reserve to the east of the site; The property nos. 389-391 Liverpool Road to the south and west of the site, which

is occupied by a three storey brick residential building, along the site southern boundary, and a concrete access driveway to the building along the site western boundary.

The site topography during the investigation was generally level with a gently slope towards the west. The local topography was also generally level with a gentle sloping towards the west.

5. PROPOSED DEVELOPMENT

The architectural drawings (referenced in Section 2) indicate the proposed development consists of demolition of the existing buildings and construction of a three storey residential building with one basement level for underground carpark. Vehicular access to the basement will be via a ramp from High Street along the site western boundary.


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The elevation of the proposed lower basement floor is 31.00m Australian Height Datum (AHD), requiring a maximum excavation depth of approximately 5.0m for construction of the single basement level. The proposed lift shaft, which is proposed to be located within the middle portion of the proposed building is anticipated to require a further 1.5m of excavation below the basement Finished Floor Level (FFL).

6. SUBSURFACE CONDITIONS

6.1 Geology

Reference to the Sydney 1:100,000 Geological Series Sheet 9130 Edition 1, dated 1983, by the Geological Survey of New South Wales, Department of Mineral Resources, indicates the site is located at a geological boundary underlain by Triassic Age Bringelly Shale (Rwb) of the Wianamatta Group. The Bringelly Shale (Rwb) is described as “Shale, carbonaceous claystone, claystone, laminate, fine to medium-grained lithic sandstone, rare coal and tuff”.

The site is also located approximately 110m to the north of the Fairfield Basin, which is an area underlain by an anticline fold geological system.

Assessment of the subsurface materials, discussed in Section 6.2, confirms the published geology.

It should be noted this geological profile does not take into account the residual soils derived from in-situ weathering of the bedrock, or the presence of fill that may have been generated from previous earthworks.

6.2 Ground Profile

The subsoil conditions encountered within the boreholes are summarised in Table 1 and detailed on the attached Engineering Borehole Logs presented in Appendix C. It should be noted that reference should be made to the logs and/or specific test results for design purposes.

Table 1: Summary of Subsurface Conditions

Unit Description BH1 (m) BH2 (m) BH3 (m)

Ground Surface Level (m AHD) RL34.2 RL34.3 RL35.1

Fill Silty SAND, fine grained, dark grey to brown, some

medium plasticity clay, grass rootlets, loose. 0.0 – 0.4 0.0 – 0.6 0.0 – 0.6

Residual

Soils

Silty CLAY, medium to high plasticity, brown to pale

grey, firm to very stiff. 0.4 – 1.5 0.6 – 1.3 0.6 – 1.0

Silty CLAY, medium to high plasticity, brown to pale

grey, shale laminations, very stiff to hard. 1.5 – 1.8 1.3 – 1.7 1.0 – 1.2

Bedrock SHALE, pale brown to grey, extremely weathered,

extremely low strength. Class V Shale1. 1.8 – 6.2+ 1.7 – 4.5+ 1.2 – 6.8+

1Pells P.J.N, Mostyn G. & Walker B.F. Foundations on Sandstone and Shale in the Sydney Region, Australian Geomechanics Journal,

December 1998 (Reference 6).


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6.3 Groundwater

Groundwater was not encountered during augering in boreholes BH1 to BH3 inclusive. However, it should be noted that the absence of groundwater during the investigation does not preclude its presence.

It is inferred that natural groundwater levels may be in the form of seepage through fissures and natural defects in the underlying weathered bedrock, at depths below the proposed basement level.

Further, it should be noted that groundwater levels may be subject to seasonal and daily fluctuations influenced by factors such as rainfall and future development of the surrounding lands. Soil moisture within the site may be influenced by events within the property and the adjoining road and properties such as breakage of water mains, or stormwater pipes.

7. GEOTECHNICAL ASSESSMENT

7.1 General

Based on the basement level of approximately 31.00m AHD, it is considered that the bulk excavation will be predominately in the underlying fill material, residual soils and shale bedrock.

Consideration needs to be given to specific geotechnical issues including excavation requirements and foundation conditions. Geotechnical commentary regarding these geotechnical constraints and recommendations for the proposed development is presented in the following sections.

7.2 Excavation Conditions

The observations made during the investigation indicate the existing buildings and associated concrete slabs cover the majority of the footprint of the proposed development. Thereafter, excavation is expected to be through fill and residual soils and then into shale bedrock of varying strength and weathering.

Excavation within soils and very low to low strength shale is expected to be readily achieved using a large hydraulic excavator down to the level of medium or stronger bedrock. However, localised use of rock breaking equipment or ripping may be required where high strength bands are encountered.

For medium or greater strength rock (if encountered), excavation would require the use of heavy ripping and/or hydraulic rock hammers. Excavation for foundations or trenches may require the use of hydraulic hammers and possibly a rock saw. Both noise and vibration will be generated by the proposed excavation work within these bedrock materials, if encountered.


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7.3 Vibration Control

Consideration should be given to a vibration monitoring plan to monitor the potential vibration effects from the demolition works on existing buildings within adjoining properties and road reserves and carriageways along the site boundary.

To ensure vibration levels remain within acceptable levels and to minimise the potential effects of vibration, if required, excavation into medium strength bedrock or stronger (if encountered) should be complemented with saw cutting or other appropriate methods prior to excavation. Rock saw cutting should be carried out using an excavator mounted rock saw, or similar, so as to minimise transmission of vibrations to any adjoining properties that may be affected. Hammering is not recommended and should be avoided. However, if necessary, hammering should be carried out horizontally along bedding planes of (pre-cut) broken rock blocks or boulders where possible and at the required operational limit to ensure noise levels are restricted to limits acceptable to adjacent residents.

Recommended Maximum Peak Particle Velocity (PPV) for different types of building or structure is summarised in Table 2. Induced vibrations in structures adjacent to the excavation should not be exceeded.

Table 2: Recommended Maximum Peak Particle Velocity

Type of Building or Structure Max. PPV (mm/sec)

Historical or structures in sensitive conditions 2

Residential and low rise buildings 5

Brick or unreinforced structures in good condition 10

Commercial and industrial buildings or structures of reinforced concrete or steel construction.

25

It is recommended that monitoring is carried out during excavation using a vibration monitoring instrument (seismograph) and alarm levels (being the appropriate PPV) selected in accordance with the type of structures present within the zone of influence of the proposed excavation.

If vibrations in adjacent structures exceed the above values or appear excessive during construction, excavation should cease and the project Geotechnical Engineer should be contacted immediately for appropriate reviews.

It is recommended a dilapidation survey of the existing buildings within adjoining properties and infrastructure is conducted. Preparation of dilapidation survey report and vibration monitoring plan together with vibration monitoring should constitute as “Hold Points”.

7.4 Stability of Excavation

Temporary batter slopes may be considered in areas where sufficient space exists between the basement excavation and the boundary or where an adjacent property is outside a zone of influence obtained by drawing a line up at 45° from the toe of the proposed excavation.


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Even where shoring is provided for excavations occurring within this zone of influence, consideration should be given to inspection pits to investigate the requirement for underpinning in any affected adjacent properties. Recommended maximum slopes for temporary batters are provided in Table 3 below.

Table 3: Recommended Batter Slopes (Temporary)

Material Max. Batter Slope (H:V)

Fill and Residual Soil 1:1

Class V Shale 0.75:1

As excavation of the proposed basements will extend to approximately 5.0m depth and due to the close proximity of the basement with the boundaries, the use of temporary batters will be precluded in most areas and therefore temporary shoring should be provided. Shoring design should consider both short term (construction) and permanent conditions as well as the presence of adjacent buildings and roads.

Based on the ground conditions encountered and the requirements of the proposed development, we recommend a contiguous pile wall solution socketed into the underlying Shale bedrock to at least 1.0m below basement level. The use of contiguous pile walls allow a small gap between piles which could allow significant groundwater inflow (if present) during excavation. The use of strip drains behind the piles and shotcreting in weak areas susceptible to inflow during excavation, can limit the amount of any groundwater ingress. All vertical drains should be connected to a geofabric wrapped perimeter drain provided at the toe of the final excavation, which should discharge to the site stormwater system to provide long term drainage behind excavation walls.

For the maximum retained height being considered, a temporary anchorage system is likely to be required at some locations to provide the required lateral support during construction. Where the retained height is such that tolerable wall movements can be achieved using a cantilevered wall arrangement (less than 2.5m) or where only one row of anchors is required to provide lateral support, a triangular pressure distribution may be adopted for derivation of active pressures. Where two or more rows of anchors are required to support the shoring due to increased retained height or where significant lateral movements cannot be tolerated (e.g. due to adjacent infrastructure), the shoring/basement wall should be designed as a braced structure. Anchors should be angled down to be embedded in the bedrock.

Anchor designs should be based on allowing effective bonding to be developed behind an ‘active zone’ determined by drawing a line at 45° from the base of the wall to intersect the ground surface behind the excavated face. It is considered that basement floor slabs will provide permanent restraint to the retaining walls where these are incorporated into the permanent works. Anchors are therefore considered to be temporary; however, depending


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on the sensitivity of the adjacent infrastructure, it may be necessary to incorporate the temporary anchors into the permanent works to control deflections.

Anchor installation beyond the property boundaries will be subject to approval by owners of adjoining properties, roads and infrastructure. Where an anchorage system is shown to be impractical, consideration of other temporary support options would be necessary. These options include the following:

Temporary solutions such as installation of props associated with staged excavation; and

Staged excavations and temporary partial berms in front of walls. Top-down construction where floor slabs and beams are constructed at the top of

shoring wall and at floor levels of the upper basement levels prior to excavation within the basement level underneath the floor slabs.

The shoring wall and anchors can be designed using the recommended parameters provided in Section 7.5 below.

Geotechnical stress-deformation analysis using finite element or finite difference methods should be carried out during the detailed design stage in order to determine the effects of the basement excavation on the adjoining properties and public roads.

A dilapidation survey will be required prior to excavation for the existing buildings within the adjoining properties and the section of road carriageway and road reserve adjoining the site.

Detailed construction supervision, monitoring and inspections will be required during piling and subsequent bulk excavation and should be carried out by an experienced Geotechnical Engineer, in addition to inspection of the structural elements by the Project Structural Engineer. The inspections should constitute as “Hold Points”.

7.5 Earth Pressures

Earth retaining structures should be designed to withstand the lateral earth pressure, hydrostatic and earthquake (if applicable) pressures, and the applied surcharge loads in their zone of influence, including existing structures, traffic and construction related activities.

For the design of flexible retaining structures, where some lateral movement is acceptable, it is recommended the design should be based on active lateral earth pressure. Should it be critical to limit the horizontal deformation of a retaining structure, use of an earth pressure coefficient “at rest” should be considered such as the case when the shoring wall is in the final permanent state and is restrained by the concrete slab in its final state.

Recommended parameters for the design of earth retaining structures in the soils and rock horizons underlying the site are presented in Table 4.


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Table 4: Preliminary Geotechnical Design Parameters for Retaining Walls

Units Unit Weight

(kN/m3)

Effective Cohesion c’

(kPa)

Angle of Friction ′

()

Modulus of Elasticity Esh

(MPa)

Fill 17 0 26 8

Residual Soils 20 5 24 15

Class V Shale 22 25 27 65

Class IV Shale1 22 50 28 200 1 Class IV Shale was not encountered during the site investigation. However, it is inferred that Class IV Shale underlays

Class V Shale at depths below ‘TC’ bit refusal in each borehole. The actual depth of the underlying Class IV Shale should

be confirmed during construction.

Table 5 below provides preliminary coefficients of lateral earth pressure for the soils and rocks encountered during the geotechnical investigation. The coefficients provided are based on horizontal ground surface and fully drained conditions.

Table 5: Preliminary Coefficients of Lateral Earth Pressure

Units Coefficient of Active

Lateral Earth Pressure Ka

Coefficient of Active Lateral Earth

Pressure at Rest Ko

Coefficient of Passive Lateral Earth Pressure Kp

Fill 0.39 0.56 2.56

Residual Soils 0.42 0.59 2.37

Class V Shale 0.3 0.5

3.0

Class IV Shale1 3.0 1 Class IV Shale was not encountered during the site investigation. However, it is inferred that Class IV Shale underlays


be confirmed either during construction.

Coefficient of active and passive lateral earth pressure Ka and Kp, respectively, can be calculated using Rankine’s or Coulomb’s equations, as appropriate.

Coefficient of lateral earth pressure at rest Ko for soils, can be calculated using Jacky’s equation.

The coefficients of lateral earth pressure should be verified by the project Structural Engineer prior to use in the design of retaining walls. Simplified calculations of lateral active (or at rest) and passive earth pressures can be carried out for cantilever walls using Rankine’s equation shown below:

2 √ For calculation of lateral active or ‘at rest’ earth pressure

2 For calculation of passive earth pressure

For braced retaining walls, a uniform lateral earth pressure should be adopted as follows;


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0.65 For calculation of active earth pressure

where, Pa = Active (or at rest) Earth Pressure (kN/m2) Pp = Passive Earth Pressure (kN/m2) = Bulk density (kN/m3) K = Coefficient of Earth Pressure (Ka or Ko) Kp = Coefficient of Passive Earth Pressure H = Retained height (m) c = Effective Cohesion (kN/m2)

If adopted, temporary anchors will require embedment in Class V Shale. A preliminary allowable bond stress of 50kPa may be adopted for temporary anchors within Class V Shale.

Anchors should undergo proof testing following installation. The anchors can be designed for the parameters recommended above providing:

The bond (socket) length in Class V Shale or better at least 3.0m; and Anchors are proof tested to 1.3 times the design working load specified by the

Structural Engineer, before they are locked off at working load. Anchor testing should constitute as a “Hold Point”.

7.6 Subgrade Preparation and Earthworks

The following general procedure is provided for site preparation of building platforms and pavements:

Strip topsoil and remove any unsuitable material from site. Excavate fill, residual soils and rock (if encountered) stockpiling for re-use as

engineered fill or remove to spoil. Where clayey soil is exposed at formation level, the exposed surface should be

treated and moisture conditioned to within 2% of optimum moisture content (OMC) followed by proof rolling with a smooth drum roller. Soft or loose areas should be excavated and replaced with approved fill material.

Where rock is exposed at footing level, it should be free of loose or softened material.

The suitability of imported materials for filling should be subject to the following criteria:

The materials should be clean (i.e. free of contaminants, deleterious or organic material), free of inclusions of >120mm in size; high plasticity material and soft material be removed and suitably conditioned to meet the design assumptions where fill material is proposed to be used.

Material with excessive moisture content should not be used without conditioning. The materials should satisfy the Australian Standard AS 3798-2007 (Reference 3).

The final surface levels of all cut and fill areas should be compacted in order to enable the subgrade to achieve adequate strength for the proposed building platforms.


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For the fill construction, the recommended compaction targets should be the following:

Moisture content of ±2% of OMC (Optimal Moisture Content); Minimum density ratio of 98% of the maximum dry density for the building

platforms of the proposed dwellings; The loose thickness of layer should not exceed 300mm during the compaction.

Design and construction of earthworks should be carried out in accordance with Australian Standard AS 3798-2007 (Reference 3).

Inspections by the project Geotechnical Engineer will be required during earthworks, subgrade preparation and proof rolling. The inspections should constitute as “Hold Points”.

7.7 Foundations

Bulk excavation is mainly likely to expose variable strength bedrock at lower basement level. Suitable footings are therefore likely to comprise a slab on grade for the basement and shallow strip and pad footings supporting internal columns and walls.

However, given the potential for variable ground conditions at bulk excavation level, it is recommended that all footings be founded on consistent subsurface materials to minimise the risk of differential settlement. This could be achieved by strip footings where suitable bedrock is exposed at bulk excavation level and shallow pad or pile foundations elsewhere.

Table 6 provides geotechnical parameters recommended for design of shallow and piled foundations.

Table 6: Preliminary Geotechnical Foundation Design Capacities

Unit

Allowable Capacity Values (kPa)

End Bearing Pressure1

Shaft Adhesion Compression

(Tension)2

Fill N/A3 N/A3

Residual Soils 100 N/A3

Class V Shale 700 25 (15)

Class IV Shale4 1,000 100 (50) 1 With a minimum embedment depth of 0.5m for deep foundations and 0.4m for shallow foundations.

2 Clean rock socket of roughness of at least grooves of depth 1mm to 4mm and width greater than 5mm at spacing of

50mm to 200mm.Shaft Adhesion in Tension is 50% of Compression, applicable to piles only.

3 N/A, Not Applicable, not recommended for the proposed building of this development.

4 Class IV Shale was not encountered during the site investigation. However, it is inferred that Class IV Shale underlays


be confirmed during construction.


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The excavations should be dewatered prior to concrete pouring if groundwater seepages or surface runoff are encountered within foundation excavations. Any loose debris and wet soils should also be removed from excavations.

An experienced Geotechnical Engineer should review footing designs to ensure compliance with the recommendations in the geotechnical report and assess foundation excavations to ensure suitable materials of appropriate bearing capacity have been reached. The presence of water within foundation excavations may negate satisfactory examination of founding surfaces and certification of founding materials quality. Foundation inspections should only be undertaken under conditions satisfying WHS requirements.

Verification of the capacity of the shallow and pile foundations by inspections would be required and inspections should constitute as “Hold Points”.

7.8 Groundwater Management

Although groundwater was not encountered during the investigation, seasonal variations resulting in elevated groundwater levels (e.g. due to heavy rainfall, broken services, etc.) may increase seepage during excavation or in the long term during the design life of the building. It would therefore be prudent to give consideration to precautionary drainage measures in the design and construction of the proposed development. Such measures could include the following:

Strip drains or drainage materials should be installed behind the shoring/retaining walls in conjunction with collection trenches or pipes and pits connected to the building stormwater system. A temporary storage tank and pump system may be required.

Groundwater seepage (if encountered) and surface water infiltration should be controlled by a sump and pump methods during construction.

Inspection of the groundwater management system and monitoring during dewatering would be required and inspections and monitoring should constitute as “Hold Points”.

7.9 Preliminary Site Earthquake Classification

The results of the site investigation indicate the presence of fill and residual soil extending from approximately 1.2m to 1.8m depth within the site to approximately, and underlain by extremely low strength Class V Shale to depths ranging from approximately 4.5m to 6.8m. In accordance with Australian Standard AS 1170.4-2007 (Reference 2) the site may be classified as a “Shallow soil site” (Class Ce) for design of foundations and retaining walls embedded in the underlying soils and weathered Shale. The Hazard Factor (Z) for Sydney in accordance with AS 1170.4-2007 is considered to be 0.08.

8. LIMITATIONS

The geotechnical assessment of the subsurface profile and geotechnical conditions within the proposed development area and the conclusions and recommendations presented in this report have been based on available information obtained during the work carried out by Aargus and in the provided documents listed in Section 2 of this report. Inferences about


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the nature and continuity of ground conditions away from and beyond the locations of field exploratory tests are made, but cannot be guaranteed.

It is recommended that should ground conditions including subsurface and groundwater conditions, encountered during construction and excavation vary substantially from those presented within this report, Aargus Pty Ltd be contacted immediately for further advice and any necessary review of recommendations. Aargus does not accept any liability for site conditions not observed or accessible during the time of the inspection.

This report and associated documentation and the information herein have been prepared solely for the use of Dora Christodoulides and any reliance assumed by third parties on this report shall be at such parties’ own risk. Any ensuing liability resulting from use of the report by third parties cannot be transferred to Aargus Pty Ltd, directors or employees.

The conclusions and recommendations of this report should be read in conjunction with the entire report.

For and on behalf of

Aargus Pty Ltd

Reviewed By

Joe Nader

BE (Civil), Dip.Eng.Prac., GradIEAust

Geotechnical Engineer

Kenneth Burgess B.Eng., Pg.Dip., MIEAust

Principal Geotechnical Engineer

National Engineering Manager

APPENDIX A

_____________________________ IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL REPORT

IMPORTANT INFORMATION ABOUT YOURGEOTECHNICAL ENGINEERING REPORT

More construction problems are caused by sitesubsurface conditions than any other factor. Astroublesome as subsurface problems can be, theirfrequency and extent have been lessenedconsiderably in recent years, due in largemeasure to programs and publications of ASFE/The Association of Engineering Firms Practicingin the Geosciences.

The following suggestions and observations areoffered to help you reduce the geotechnical-related delays, cost-overruns and other costlyheadaches that can occur during a constructionproject.

A GEOTECHNICAL ENGINEERING

REPORT IS BASED ON A UNIQUE SET

OF PROJECT-SPECIFIC FACTORS

A geotechnical engineering report is based on asubsurface exploration plan designed toincorporate a unique set of project-specificfactors. These typically include the generalnature of the structure involved, its size andconfiguration, the location of the structure on thesite and its orientation, physical concomitantssuch as access roads, parking lots, andunderground utilities, and the level of additionalrisk which the client assumed by virtue oflimitations imposed upon the exploratoryprogram.

To help avoid costly problems, consult thegeotechnical engineer to determine how anyfactors which change subsequent to the date ofthe report may affect its recommendations.

Unless your consulting geotechnical engineerindicates otherwise, your geotechnicalengineering report should NOT be used:

when the nature of the proposed structure ischanged: for example, if an office building willbe erected instead of a parking garage, or if arefrigerated warehouse will be built instead ofan un-refrigerated one,

when the size or configuration of the proposedstructure is altered,

when the location or orientation of the proposedstructure is modified,

when there is a change of ownership, or

for application to an adjacent site.

Geotechnical engineers cannot acceptresponsibility for problems which may develop ifthey are not consulted after factors considered intheir report's development have changed.

Geotechnical reports present the results ofinvestigations carried out for a specific project andusually for a specific phase of the project. Thereport may not be relevant for other phases of theproject, or where project details change.

The advice herein relates only to this project and thescope of works provided by the Client.

Soil and Rock Descriptions are based on AS1726-1993, using visual and tactile assessment except atdiscrete locations where field and/or laboratory testshave been carried out. Refer to the attached termsand symbols sheets for definitions.

MOST GEOTECHNICAL "FINDINGS"

ARE PROFESSIONAL ESTIMATES

Site exploration identifies actual subsurfaceconditions only at those points where samples aretaken, when they are taken. Data derived throughsampling and subsequent laboratory testing areextrapolated by geotechnical engineers who thenrender an opinion about overall subsurfaceconditions, their likely reaction to proposedconstruction activity, and appropriate foundationdesign. Even under optimal circumstances actualconditions may differ from those inferred to exist,because no geotechnical engineer, no matter how

_______________________________________________________________________________________Page 2 of 3 Important Information About Your Geotechnical Engineering Report

qualified, and no subsurface explorationprogram, no matter how comprehensive, canreveal what is hidden by earth, rock and time.The actual interface between materials maybe far more gradual or abrupt than a reportindicates. Actual conditions in areas notsampled may differ from predictions. Nothingcan be done to prevent the unanticipated, butsteps can be taken to help minimize theirimpact. For this reason, most experiencedowners retain their geotechnical consultantsthrough the construction stage, to identifyvariances, conduct additional tests which maybe needed, and to recommend solutions toproblems encountered on site.

SUBSURFACE CONDITIONS CAN

CHANGE

Subsurface conditions may be modified byconstantly changing natural forces. Because ageotechnical engineering report is based onconditions which existed at the time ofsubsurface exploration, construction decisionsshould not be based on a geotechnicalengineering report whose adequacy may havebeen affected by time. Speak with thegeotechnical consultant to learn if additionaltests are advisable before construction starts.

Construction operations at or adjacent to thesite and natural events such as floods,earthquakes or groundwater fluctuationsmay also affect subsurface conditions, andthus, the continuing adequacy of a geotechnicalreport. The geotechnical engineer should bekept apprised of any such events, and should beconsulted to determine if additional tests arenecessary.

Subsurface conditions can change with timeand can vary between test locations.Construction activities at or adjacent to the siteand natural events such as flood, earthquake orgroundwater fluctuations can also affect thesubsurface conditions.

GEOTECHNICAL SERVICES ARE

PERFORMED FOR SPECIFIC

PURPOSES AND PERSONS

Geotechnical engineers’ reports are prepared to meetthe specific needs of specific individuals. A reportprepared for a consulting civil engineer may not beadequate for a construction contractor, or even someother consulting civil engineer. Unless indicatedotherwise, this report was prepared expressly for theclient involved and expressly for purposes indicatedby the client. Use by any other persons for anypurpose, or by the client for a different purpose, mayresult in problems.No individual other than the client should applythis report for its intended purpose without firstconferring with the geotechnical engineer. Noperson should apply this report for any purposeother than that originally contemplated withoutfirst conferring with the geotechnical engineer.

A GEOTECHNICAL ENGINEERING

REPORT IS SUBJECT TO

MISINTERPRETATION

Costly problems can occur when other designprofessional develop their plans based onmisinterpretations of a geotechnicalengineering report. To help avoid theseproblems, the geotechnical engineer should beretained to work with other appropriate designprofessionals to explain relevant geotechnicalfindings and to review the adequacy of theirplans and specifications relative togeotechnical issues.

The interpretation of the discussion andrecommendations contained in this report are basedon extrapolation/interpretation from data obtained atdiscrete locations. Actual conditions in areas notsampled or investigated may differ from thosepredicted

BORING LOGS SHOULD NOT BE

SEPARATED FROM THE ENGINEERING

REPORT

Final boring logs are developed bygeotechnical engineers based upon theirinterpretation of field logs (assembled by sitepersonnel) and laboratory evaluation of fieldsamples. Only final boring logs customarilyare included in geotechnical engineeringreports. These logs should not under anycircumstances be redrawn for inclusion inarchitectural or other design drawings becausedrafters may commit errors or omissions in the

_______________________________________________________________________________________Page 3 of 3 Important Information About Your Geotechnical Engineering Report

transfer process. Although photographicreproduction eliminates this problem, itdoes nothing to minimize the possibilityof contractors misinterpreting the logsduring bid preparation. When this occurs,delays, disputes and unanticipated costsare the all-too-frequent result.

To minimise the likelihood of boring logmisinterpretation, give contractors readyaccess in the complete geotechnicalengineering report prepared or authorizedfor their use. Those who do not providesuch access may proceed under mistakenimpression that simply disclaimingresponsibility for the accuracy ofsubsurface information always insulatesthem from attendant liability. Providingthe best available information tocontractors helps prevent costlyconstruction problems and the adversarialattitudes which aggravate them todisproportionate scale.READ RESPONSIBILITY

CLAUSES CLOSELY

Because geotechnical engineering is basedextensively on judgment and opinion, it isfar less exact than other designdisciplines. This situation has resulted inwholly unwarranted claims being lodgedagainst geotechnical consultants. To helpprevent this problem, geotechnicalengineers have developed model clausesfor use in written transmittals. These arenot exculpatory clauses designed to foistgeotechnical engineers’ liabilities ontosomeone else. Rather, they are definitiveclauses which identify where geotechnicalengineers' responsibilities begin and end.Their use helps all parties involved rec-ognize their individual responsibilitiesand take appropriate action. Some ofthese definitive clauses are likely toappear in your geotechnical engineeringreport, and you are encouraged to readthem closely. Your geotechnical engineerwill be pleased to give full and frankanswers to your questions.

OTHER STEPS YOU CAN TAKE TO

REDUCE RISK

Your consulting geotechnical engineerwill be pleased to discuss other

techniques which can be employed to mitigaterisk. In addition, ASFE has developed avariety of materials which may be beneficial.Contact ASFE for a complimentary copy of itspublications directory.

FURTHER GENERAL NOTES

Groundwater levels indicated on the logs are takenat the time of measurement and may not reflect theactual groundwater levels at those specific locations.It should be noted that groundwater levels canfluctuate due to seasonal and tidal activities.

This report is subject to copyright and shall not bereproduced either totally or in part without theexpress permission of the Company. Whereinformation from this report is to be included incontract documents or engineering specifications forthe project, the entire report should be included inorder to minimise the likelihood ofmisinterpretation.

APPENDIX B

_______________________________ SITE PLAN (FIGURE 1)

Image Source: Site Survey plan titled “Detail Survey 387 Liverpool Road, Strathfield” prepared by Benchmark Surveys Pty Ltd, referenced No. 141019 and dated 13th October 2014.

Aargus Environmental – Remediation – Engineering – Drilling – Laboratories

Drawn JN Dora Christodoulides

Geotechnical Investigation 387 Liverpool Road, Strathfield, NSW 2135

Figure

1 Checked KB

Title Site Plan Date 20/05/2016

Scale @ A3 NTS Job No GS6528-1A

LEGEND: (approximate)

Borehole Locations

BH1BH2

BH3

APPENDIX C

______________________________ ENGINEERING BOREHOLE LOGS

AD

T

NO

T E

NC

OU

NT

ER

ED

FILL

RESIDUAL SOILS

BEDROCK

'TC' Bit refusal at 6.2m bgl.

DS

SPT6, 11, 19/110mm

BouncingPP=300kPa

DS

SP

CI-CH

Silty SAND, fine grained, dark grey-brown, some medium plasticity clay, grass rootlets,moist, loose.

Silty CLAY, medium to high plasticity, brown-pale grey, some red mottling, moist, firmto stiff.

becoming very stiff to hard from 1.5m bgl.some Shale laminations observed from 1.6m bgl.

SHALE, pale brown, some pale grey laminations, extremely weathered, extremely lowstrength, minor clay bands in the upper layers.

harder to auger from 4.0m bgl.

very hard to auger from 5.7m bgl.

Borehole BH1 terminated at 6.2m

Met

hod

Wat

er

Additional ObservationsSamples

TestsRemarks

BOREHOLE NUMBER BH1PAGE 1 OF 1

COMPLETED 16/4/8DATE STARTED 16/4/8

DRILLING CONTRACTOR BG Drilling Pty Ltd

LOGGED BY JN CHECKED BY MM

NOTES RL to the top of borehole and depths of the subsurface conditions are approximate

HOLE LOCATION Refer to Site Plan Figure 1EQUIPMENT Dando Terrier

HOLE SIZE 100mm Diameter

R.L. SURFACE 34.2 DATUM m AHD

SLOPE 90° BEARING ---

CLIENT Dora Christodoulides

PROJECT NUMBER GS6528-1A

PROJECT NAME Geotechnical Investigation

PROJECT LOCATION 387 Liverpool Road, Strathfield, NSW 2135

BO

RE

HO

LE /

TE

ST

PIT

GS

6528

.GP

J G

INT

ST

D A

US

TR

ALI

A.G

DT

16/

4/1

4Aargus Pty Ltd446 Parramatta RoadPetersham NSW 2049Telephone: 1300 137 038

RL(m)

34

33

32

31

30

29

28

Depth(m)

1

2

3

4

5

6

7

Cla

ssifi

catio

nS

ymbo

l

Gra

phic

Log

Material Description

AD

T

NO

T E

NC

OU

NT

ER

ED

FILL

RESIDUAL SOILS

BEDROCK


DS

SPT7, 15/50mmBouncing

PP=>450kPa

DS

SP

CI-CH

Silty SAND, fine grained, dark grey-brown, some medium plasticity clay, grass rootlets,moist, loose.

Silty CLAY, medium to high plasticity, brown-pale grey, moist, firm to stiff.

some Shale laminations observed from 1.3m bgl.

becoming very stiff to hard from 1.5m bgl.

SHALE, pale brown, extremely weathered, extremely low strength, moist.

hard to auger from 3.8m bgl.

becoming pale brown-grey from 4.0m bgl.

very hard to auger from 4.2m bgl.


Met

hod

Wat

er


TestsRemarks














BO

RE

HO

LE /

TE

ST

PIT

GS

6528

.GP

J G

INT

ST

D A

US

TR

ALI

A.G

DT

16/

4/1


RL(m)

34

33

32

31

30

29

28

Depth(m)

1

2

3

4

5

6

7

Cla

ssifi

catio

nS

ymbo

l

Gra

phic

Log


AD

T

NO

T E

NC

OU

NT

ER

ED

FILL

RESIDUAL SOILS

BEDROCK


DS

SPT5/50mmBouncing

DS

SP

CI-CH

Silty SAND, fine grained, dark brown-grey, grass rootlets, moist, loose.

Silty CLAY, medium to high plasticity, brown-pale grey, moist, stiff.

Shale laminations observed from 1.0m bgl.

SHALE, pale brown-grey, extremely weathered, extremely low strength, moist.

becoming pale brown from 2.5m bgl.

harder to auger from 2.7m bgl.

becoming pale grey-brown from 5.0m bgl.

becoming brown from 6.0m bgl.


Met

hod

Wat

er


TestsRemarks














BO

RE

HO

LE /

TE

ST

PIT

GS

6528

.GP

J G

INT

ST

D A

US

TR

ALI

A.G

DT

16/

4/1


RL(m)

35

34

33

32

31

30

29

Depth(m)

1

2

3

4

5

6

7

Cla

ssifi

catio

nS

ymbo

l

Gra

phic

Log


no. 387 liverpool road strathfield nsw 2135 · reference to the sydney 1:100,000 geological series...

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